1. Field of the Invention
The invention relates to a closure with self-closing valve. The closure can be used in particular with tubes, cans, bags and bottles preferably containing pasty or liquid substances.
2. Prior Art
EP-A-395 380 describes a liquid dispenser with a self-closing valve. The self-closing valve has a surrounding flange, a peripheral surface extending therefrom and a cover surface with a slit provided therein. The self-closing valve is arranged in the dispensing opening of a container, whereby the valve flange is held by a retaining ring on the edge of the dispensing opening. For delivery of liquid from the container, pressure is exerted thereon causing the self-closing valve to first be turned outwards, i.e. the valve is curved from a resting position in the region of its peripheral surface in such a way that the cover surface comes outwards. In the turned-outwards position, the slit is widened to form a dispensing opening as a result of the pressure exerted on the container. When the pressure on the container is reduced, the slit closes automatically and the valve arrives in its resting position by turning inwards. The container is ventilated by means of the slit which opens as a result of the partial vacuum in the container. This system is eminently suitable for many applications, particularly for use in containers which are stored with the opening facing downwards so that the product to be dispensed can be dispensed immediately by means of pressure on the container, such as e.g. for shower gel, shampoo or the like. It has turned out that the container ventilation of this well-known closure system does not always work reliably. With thin-walled containers in particular, this results in the container not returning to its original shape, but the container walls remaining in the pressed-in position.
EP-A-0 545 678 discloses a closure with a self-closing valve comprising a ring-shaped flange, a cylindrical peripheral surface extending from the flange and a cover surface having a cross slit therein. The valve's annular flange is L-shaped and is fixed at the dispensing opening of a container by means of a retaining ring. When the valve is in the resting position, the cover surface of the cylindrical peripheral surface is turned inside the dispensing opening. Pressure on the container causes the valve to turn outwards and even more pressure causes the cross slit to open up. When the pressure is reduced, the valve returns to its resting position. The container is ventilated by opening the cross slit in the resting position. Furthermore, a lid or a slide is provided which prevents unintentional dispensing of the product contained in the container. When the lid is closed, the self-closing valve cannot be turned outwards.
U.S. Pat. No. 5,115,950 describes a closure with a self-closing valve. The valve comprises a ring-shaped flange with a trapezoidal cross section which becomes thicker towards the outside. A peripheral surface that is directed towards the outside extends from the annular flange and a cover surface being curved inwards and having a cross slit extending from there. A cup is located inside the dispensing opening adjacent to the interior of the cover surface. This cup is held at the internal wall of the dispensing opening by means of bridges. Furthermore, the closure has a lid with two surrounding projections at the inside, which projections are in contact with the valve at the upper edge of the peripheral surface and in the area of the cup-shaped depression and press against the cup when the lid is closed. This is to prevent an undesired dispensing of the container's content. In this known closure, the ring-shaped flange is clamped between a locating face and a bendable bracket. Either the locating face or the bracket may have tooth-like projections that are to serve for an improved clamping of the annular flange.